Revert "Update to DataNucleus 4"

This reverts commit 5e710729cf24782c596d6a2baf8b5974d7ef51fd.

After above commit, S2 tests started to fail.  The underlying
problem is presented as a org.datanucleus.exceptions.NucleusUserException
with the following message

    Could not create new "sequence" "pin_sequence" since autoCreate
    flags do not allow it.

For the S2 tests, the message is always the same and appears to
originate from pin-manager.

I've reverting this patch at Gerd's request.

04 Jul 2014 12:20:18 (SRM-sisyphus) [131.169.72.210:53318 45M:33:srm2:prepareToGet:-2147482625:-2147482624] Uncaught exception in thread pool-11-thread-9